/Engine/Plugins/Online/OnlineSubsystemUtils/Source/OnlineSubsystemUtils/Classes/IpNetDriver.h
Callback for platform handling when networking is taking a long time in a single frame (by default over 1 second). It may get called multiple times in a single frame if additional processing after a previous alert exceeds the threshold again
typedef TMulticastDelegate_NoParams< void > FOnNetworkProcessingCausingSlowFrame